In this type of system, communications are generally processed as a data stream. Different processors or processing hardware blocks of different computation nodes perform processing operations on data sequentially transmitted from one processor or processing hardware block to another. By “processing hardware block”, we mean a hardware device wherein the processing operations are performed by fixed electronic circuits and not by a processor executing a computer program. The memory and computation resources being distributed, there is no physical link dedicated to each data exchange but a set of processors or processing hardware blocks that share a network communication infrastructure and storage spaces distributed in the network. It therefore involves designing mechanisms and protocols making it possible to optimize the functioning of data exchanges.
In particular, two substantial properties must be taken into consideration when it is sought to optimize communications in such systems:                latency, or the time that passes between the sending of a datum and the receipt thereof,        cost, in terms of energy consumption.        
The greater the communication latencies are, the more the execution time of an application increases, which has a direct adverse effect on the performance of the system. However, the objective is also to design a system making it possible to reduce the energy expenditure for each data transmission. There is therefore a compromise to be found between performance and energy consumption in the implementation of communication mechanisms and protocols.